The apparatus and process described below rates to the formation of cementicious building blocks wherein the composition of the blocks includes fibrous material. The inclusion of fibrous material produces a block that is lighter than conventional blocks and has substantially the same strength. Inclusion of fibrous material also improves sound deadening and thermal insulating qualities of the block.
Consolidation of fibrous material in a mixture with cement and additives to form construction blocks is difficult. A correct amount of even compaction is necessary to produce an acceptable block. If there is too much compaction, the block will bulge after it is removed from the form.
My U.S. Pat. No. 3,283,384 describes an apparatus for producing such composite construction blocks. My prior patent involved two longitudinal shafts, each rotatably mounted about axes parallel to one another on a platform within a framework. The blocks in the prior apparatus were formed on the floor at the construction site. The site floor was the bottom of the block form and the apparatus contained four sides and a cover to complete the form.
In my prior invention, the apparatus was placed on the floor, a charge of mixture was placed within the form, the mixture was compressed, and the two rods were rotated eccentrically to compact the mixture.
After sufficient compaction, the rods were withdrawn from the formed block leaving cores through the block. The apparatus was then lifted from the block and the formed block was left on the floor at the construction site.
My prior invention had several disadvantages in actual practice. The machine had to be moved after each block was formed; the block required a concrete pad or other such surface as a bottom to the block form; and the machine was noisy and vibrated due to the eccentric operation of the compacting rods.